... It is not all doom and destruction. ...
I agree. I also think that a lot will depend on multiple unknowable factors such as weapon design, yield and delivery method. Much of what's been learned and disseminated about nuclear weapons effects on civilian populations was predicated on Cold War hypothesizing involving high yield weapons, air bursts, etc.
But in the meantime, increasing accuracy in delivery systems has led to the development of lower yield nukes than were deemed necessary in the past. The newer members of the Nuke Club like India, Pakistan and Israel, as far as public estimates go, also don't appear to have built very high-yield weapons either, in part because their likeliest targets are rather close by, not on the other side of the planet.
Thankfully, international arms control and accountability programs, etc., seem to have reduced the risk of a state-built nuke, or materials and experts, getting into the wrong hands, although Pakistan's stability and internal security is worrisome. Still, the risk that a non-state terrorist group might acquire or even build one remains, and from their POV there's no better place to use a nuke than against the Great Satan.
But if that happens, I think it's reasonable to expect it to be a rather low yield, ground or low-altitude detonation, which would be a catastrophe to be sure, but not a city-killer inflicting many tens or hundreds of thousands of deaths. It's even more likely, I think, to be a simple dirty bomb or an at least partially failed detonation. So most people, including many of those rather close to the detonation, can or will survive, although the result may be almost as effective for the bad guys, since it would still be "nuclear" and thus carry much the same psychological impact and likely cause similar political and economic disruptions.
The other remaining risk is an accidental nuclear attack. There have been several very close calls that we know about between us and the Russians/Soviets where somebody almost got nuked. Many experts seem to think such an accident is far more likely than an intentional use. We were only saved before because cooler heads prevailed, and, hopefully, any such future accident will not result in major nuclear exchanges.